Add QuicStringPiece which is actually StringPiece.

net/quic/platform/api/quic_url_utils.h

 // Copyright (c) 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_QUIC_PLATFORM_API_QUIC_URL_UTILS_H_
 #define NET_QUIC_PLATFORM_API_QUIC_URL_UTILS_H_
 
 #include "base/macros.h"
 #include "net/quic/platform/api/quic_export.h"
+#include "net/quic/platform/api/quic_string_piece.h"
 #include "net/quic/platform/impl/quic_url_utils_impl.h"
 
 namespace net {
 
 class QUIC_EXPORT_PRIVATE QuicUrlUtils {
  public:
   // Returns hostname, or empty std::string if missing.
-  static std::string HostName(base::StringPiece url);
+  static std::string HostName(QuicStringPiece url);
 
   // Returns false if any of these conditions occur: (1) Host name too long; (2)
   // Invalid characters in host name, path or params; (3) Invalid port number
   // (e.g. greater than 65535).
-  static bool IsValidUrl(base::StringPiece url);
+  static bool IsValidUrl(QuicStringPiece url);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(QuicUrlUtils);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_PLATFORM_API_QUIC_URL_UTILS_H_